1. Field of the Invention
The present invention relates to an image forming device.
2. Description of Related Art
A well-known conventional image forming apparatus forms a toner image on an image carrier such as a photosensitive drum through an electrophotographic process including charging, exposing, and developing, then forms the toner image on a print sheet, and fixes the toner image on a print sheet with a fixing device (e.g., Japanese Patent Application Laid-Open No. 2008-96592).
In a conventional image forming apparatus, when vibration increases due to, for example, degrading of units including a driving system or change in condition of processing system, and the vibration is transferred to an exposure unit, an optical element in the exposure unit resonates to cause image defect such as unevenness of image pitch (banding) and color registration errors, or the like. To detect occurrence of such image defects, it is required to print out and check a print sheet with an image printed thereon, or attach a vibration detecting device to monitor chronological change in vibration.
However, even by printing and checking the print sheet or by monitoring chronological change in vibration, the unit causing the increase in vibration cannot be detected. Thus, the unit still not reaching the service life without any problem is unnecessarily replaced. This disadvantageously raises service cost.